Dogs’ and cats’ eye ailments

In last month’s issue, we discussed some general eye problems our pets can have. This week we will go into detail about a couple of them.

One of the more serious ocular ailments we see is glaucoma. Glaucoma just means increased pressure inside the eye. There is fluid in the eye that helps it to keep its shape. It is not a stagnant pool, but rather it is constantly being produced and drained. If something short-circuits the drainage, then the fluid continues to accumulate and the intraocular pressure goes up. When it gets high enough, the retina becomes damaged and the pet can go blind. In people, glaucoma is generally a slow process over the course of years. In dogs (and rarely in cats) it can happen over less than 24 hours. The eye becomes very red and painful. Sometimes they will squint or paw at it and the pupil is usually quite dilated. Immediate treatment is needed if the vision is to be saved. An instrument called a tonometer is used to measure the pressure and confirm glaucoma. Eye drops and sometimes even IV injections to bring down the pressure need to be started before the retina suffers irreversible damage. Certain breeds, most notably cocker spaniels and poodles, are predisposed to developing glaucoma. It often only affects one eye to start, but generally, preventative treatment is used in the other eye because it is more likely to have the same problem at some point.A fairly common eye issue we see is corneal ulcers or corneal abrasions. The cornea is the clear surface of the front of the eyeball. It can become damaged because of inadequate tears, hair or eyelash irritation, injury or as a spontaneous occurrence. The cornea has no blood supply, but it does have a large number of nerves and damage to it causes extreme pain. Like glaucoma, pets with often squint or rub the eye and it will be red, but the pupil is often small. A dye called fluorescein is applied on the eye to highlight any scratch or ulceration. Treatment usually involves antibiotic drops and also sometimes atropine to dilate the pupil (which will decrease the pain) and anti-inflammatories. Occasionally, an ulcer will refuse to heal and in those cases, surgery is warranted to remove dead corneal tissue and encourage new growth. This procedure is called a grid keratectomy and can often be done with sedation and topical anesthetics. Sometimes, the third eyelid is subsequently sutured over the top of the eye to protect it as it heals.

One other common eye disease is cataracts. A cataract is a lens which becomes opaque so that vision is quite obscured. Unlike in people, where cataracts are commonly seen with age, in dogs and again, rarely cats, they are usually due to another underlying cause. Diabetes it the most common cause of cataracts in dogs (cats do not get diabetes-related cataracts). Other causes include previous injury and heredity. Cataracts can be removed by an ophthalmologist and an artificial lens can also be placed if desired.

The bottom line with eyes is that if it doesn’t look right or is uncomfortable for the pet, he should be seen right away. It’s better to find out that it’s maybe just some mild irritation than wait too long and discover that it was a major problem that is too late to fix.